The only reported vertebrate fossils of Cretaceous age consists of a single shark's tooth, Squalicorax pristodontus collected from an old open pit approximately 5 kilometers northwest of the community of Saline, Louisiana. This pit exposes Upper Cretaceous strata that have been uplifted by the Prothro Dome. On the basis of ostracods found within the marls and chalks exposed at the abandoned pit, the shark teeth appear to be about 66.4 to 74.5 million years old. This makes it the oldest vertebrate fossil found within Louisiana (Stringer and Henry 1996).
This is a commonly asked question that almost any geologist or paleontologists gets asked about paleontology now-a-days no matter where they live. Unfortunately, in Louisiana, all of the dinosaurs and the strata containing them are very deeply buried beneath younger strata. Except a few acres overlying both the Rayburns and Prothro Salt Domes in southern Bienville Parish, Louisiana, the sedimentary strata exposed at the surface was all deposited after the end of the Cretaceous Period, 66.4 million years, prior to when the dinosaurs became extinct. In addition, the thickness of strata deposited after the disappearance of the dinosaurs within Louisiana is hundreds to thousands of meters thick. Thus, excluding outcrops of Cretaceous rocks at two salt domes, there are no dinosaurs to be found in Louisiana because the rocks exposed at the surface are simply too young to contain dinosaurs. In addition, the Cretaceous age strata that could contain any dinosaurs are buried too deep to be examined for them.
Theoretically, it is possible to find dinosaurs in the Cretaceous rocks exposed at the Rayburns and Prothro Domes, but such finds would be extremely unlikely. First, these rocks as documented by Frey and Kaiser (1984) and Butler and Jones (1957) consisted entirely of marl, chalk, and sandstone deposited in offshore marine environments. It is highly unlikely that a bloated carcass dinosaur would have sunk on the very limited area of Cretaceous seafloors now exposed by the uplifting of the two salt domes. Finally, the Cretaceous strata at both sites has been sheared and deformed during uplift. Any large fossils, i.e. dinosaur bones, actually present would have been badly fractured, crushed, and scattered during uplift. Thus, although theoretically possible, it is extremely unlikely that any dinosaur remains will be actually found at these exposures. Both outcrops do, however, contain numerous Cretaceous invertebrate fossils, including abundant microfossils as shown by Frey and Kaiser (1984) and Butler and Jones (1957).
Butler, E. A., and Cheetham, A. H., 1957, Cretaceous ostracoda of the Prothro and Rayburns Salt Domes, Bienville Parish, Louisiana. Louisiana Geological Survey Bulletin, no. 32, 65 p., Baton Rouge, LA.
Frey, Robert C., and Kaiser, Richard D., 1984, Surface Exposures of Late Cretaceous Strata at the Rayburns Dome, Bienville Parish, Louisiana. Transactions of the Gulf Coast Association of Geological Societies. vol. 34, pp. 357-361.
Stringer, Gary L., and Henry, M., 1996, First report of the Cretaceous shark Squalicorax from Louisiana. Mississippi Geology. vol. 17, no. 2, pp. 40-42.
Copyright © 1996-2002 Paul V. Heinrich All rights reserved.